Poly(vinyl alcohol)/artificial marble wastes composites with improved melt processability and mechanical properties

The melt-processing of poly(vinyl alcohol) (PVA) is a great challenge due to its melting temperature (T-m) is very close to the initial decomposition temperature (T-i). Herein, artificial marble wastes (AMWs), a kind of calcium carbonate powder coated with unsaturated polyester, are employed as functional fillers into PVA matrix to improve its melt processability. Strong interfacial interaction is established between AMWs and PVA molecules through hydrogen bonding, and the formamide/water compound plasticizer is adopted to facilitate the intermolecular complexation between AMWs and PVA molecules. Benefiting from the nucleation effect of AMWs, the crystallite size of PVA is evidently decreased. As a result, a greatly expanded melt-processing window (T-i -T-m, 76.9 degrees C) of PVA is realized. The tensile strength of resulting composites is significantly improved by 35.4% with the incorporation of 10 wt% AMWs. We believe that our strategy will enlarge the potential applications of PVA via melt-processing and provide a new insight into the utilization of AMWs in high valuable and high-performance composites.